


Determination

by mirairai



Category: IDOLiSH7 (Video Game), Undertale (Video Game)
Genre: Flowey (Undertale) Being an Asshole, Gen, Other Additional Tags to Be Added, Riku really needs a break, apparently I like making Riku suffer-, mostly Riku's POV, per usual, stressed iori is an ooc iori, undertale crossover
Language: English
Status: In-Progress
Published: 2020-06-26
Updated: 2020-06-28
Packaged: 2021-03-04 05:33:43
Rating: General Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 2,266
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24928477
Author URL: https://archiveofourown.org/users/mirairai/pseuds/mirairai
Summary: When the other members of IDOLiSH7 disappear, Riku goes out to look for them.Although, he certainly wasn't expecting this.~Otherwise known as "Author counted 7 different souls while rewatching Undertale playthroughs and here we are-"
Kudos: 16





	1. Chapter 1

**Notes for the Chapter:**

> Welcome to the IDOLiSH7 and Undertale AU that literally no one asked for-  
> I was rewatching Undertale playthroughs when I realized Asgore needed 7 souls, and I am currently addicted to IDOLiSH7 so I connected the dots -3-  
> Even the sOUL COLOURS MATCH I-  
> Anyway, enough of me rambling, have fun reading!

Honestly, Riku would never have thought that he’d be out on a mountain. Hiking. On his own. Without the rest of IDOLiSH7. Or without anyone at all. Yet here he was, climbing Mt. Ebott alone, as slowly as he could as not to trigger an attack. Under normal circumstances, at least one of his bandmates would’ve gone with him; the group had made an entire system that made sure Riku was never alone, much to the redhead’s displeasure. He could take care of himself, he had argued, but his friends would not change their decision and had followed up on their system. 

Although, for the last couple of weeks, they hadn’t been able to do so.

It all started when Mitsuki said he was planning to go hiking a couple of weeks ago. The group had had the next three days off together, which alone was an extremely rare occurrence. They barely had a single day off together, let alone three. Nagi had, yet again, bugged everyone on what they were planning to do, and Mitsuki triumphantly pulled out a piece of paper. It was a map of a hiking path on a nearby mountain. When Riku leaned over the table to glance at the paper Mitsuki had laid across it, he noticed the top of the map – “Mt. Ebott Hiking Trail.”

At the time, everyone had agreed to go. It would be a nice change of pace from their usual busy schedule, since they could hike up at their own speed. They had set the date for the day after the next, as not to rush the preparations. But on the day between the decision and the planned hiking date, Riku had a serious attack, and Tamaki (somehow) caught a sickness that was, according to Iori, spreading across their school. It was suggested that just the Pythagoras Trio go out on hiking day, while Iori and Sogo took care of Riku and Tamaki, who had been forced into bedrest by the manager herself. They agreed upon that plan, and the four staying in the dorms said their goodbyes to the trio leaving early the next morning. Mitsuki had said that they'd be back in the next few hours as he walked away, dragging a sleepy Yamato by the sleeve, with an excited Nagi by his side.

So when the Pythagoras Trio didn't arrive at dinner time, everyone became worried. It wasn't like the four within the dorms were strict about the timing; the hike could take longer, depending on the circumstances. But with nearly twelve hours having gone by since the three left, MEZZO" and Fly Away were beginning to become antsy. Especially Iori, who had tried to call his older brother numerous times despite knowing that there was no service up on the trail. In the end, the group contacted Manager, who said that she'd try to talk to the person managing the hiking trail.

Days flew by. The hiking trail person said that he'd conduct a thorough investigation within those days, and had actually done so. But there was absolutely no trace of the three. The search was still ongoing, and with every day that passed with no results, the more the remaining four grew anxious. It certainly didn't help that the paparazzi seemed to catch on, and were now bugging the remaining members to such an extent that Tsumugi had to cancel any future jobs.

That was most likely what led Iori to making such a reckless decision later on.

The black-haired male had suddenly decided to pack up his bag, stating that he was going to look for his brother. It was clear that he wasn't thinking straight; the stress and anxiety had definitely gotten to his head. Riku, although still bedridden, tried to beg for the younger not to go, to stay and wait for the investigation to pull up something. Alas, it was to no avail, as Iori continued to pack up his things. Concerned, Sogo decided to keep an eye on Iori, pointing out that it wouldn't be ideal for him to go alone. With that, Tamaki volunteered to tag along as well. Sogo had tried to refuse him, telling him to stay with Riku and take care of him, but the mentioned redhead assured the white-haired male that he'd be just fine. Tamaki followed up with a brief statement about how he sucked at taking care of others, simply shrugging as he went to his room to pack up. Sogo, utterly defeated, sighed and went to his own room to pack up.

The very next morning, Riku smiled as the rest of his bandmates said their goodbyes, attempting not to exude any worry as they walked away. When they disappeared from sight, the center trudged back to his warm milk on the table, shoving any sort of worry from his head. He believed they'd be fine, and that they would come back later that day, the Pythagoras Trio in tow.

Obviously, that's not how it went down at all. The three didn't show up, even as hour after hour flew by. Manager, although worried and stressed as she already was, still checked in on Riku almost every day. Whether out of fear that he'd disappear as well, or just making sure that he didn't have an attack while the others were gone, he didn't know, but Tsumugi checked in on him often, giving the redhead a run-down of what they were planning to do and the results of the investigation.

The latter always came up with nothing.

A week goes by, and still nothing has changed. The rest of his group is still missing with almost no clues on where they are, and Riku is now even more secluded in the house thanks to the reporters that question him every time he sets foot out of the dorms. The stress was almost intolerable, having caused a couple of attacks already; Riku could somewhat understand Iori's train of thought now.

Thus leading him to head to Mt. Ebott himself. Not exactly the best plan, since there was a terribly high risk of him getting an attack while out, but the redhead couldn't think of anything better than that. He refused to simply wait for the investigation team to come up with something, sitting there as his stress piled up. Hopefully he could explain his decision to the President, Banri, and Manager without getting almost immediately annihilated by the President's scary scolding face…

Pondering that fact, Riku didn't notice the massive dip in the ground. He slipped on the misplaced dirt, the center falling into a dark hole. Darkness enveloped him as he fell all the way down.

He was never going to hear the end of it from the President.


	2. Chapter 2

**Summary for the Chapter:**

> Waking in a new area, Riku decides to look around.

What happened...? 

Riku slowly opened his eyes, allowing some time for his eyes to adjust to the lighting. It didn’t take all that long; wherever he was, it was relatively dark, save for some light filtering through the hole above him.

Wait, the hole above him?

The redhead glanced up, almost being immediately blinded by the light that shone down, before shutting his eyes on reflex. He averted his eyes to the floor and opened them once again, noticing the bright yellow bed of buttercups he was laying on. They must have broken his fall. After a few seconds of looking around the cave, Riku suddenly remembered how he had gotten down to where he was, to which he sighed at himself. Just how much had he not been paying attention to notice such a massive hole? Riku could already hear Iori’s scolding in his head. He’d never admit it, but the center really missed Iori’s scolding, despite how annoying he had found it in the past. You couldn’t really blame him - he had been completely alone for a week, the only thing to really keep him company being the paparazzi right outside the door. Definitely not the most ideal sort of company.

Riku lifted himself off the ground, careful not to breathe in too much pollen from the flowers that broke his fall. An attack right at that moment would most certainly not be a good thing. He glanced around the dark cave, noticing a pathway out of the cave. Clutching the strap of his backpack, he followed the trail. An arch sat at the end of the path, a small rune engraved into the top of it. It was extremely unfamiliar to him; even with all the books he had read, he had never seen such a rune before. Curious, Riku walked through the arch, entering a room about the same size as the one he was previously in. He noticed a single patch of grass in the center of the space, and after walking towards it, a single buttercup popped out of the ground.

And it had a face?

Baffled, Riku stepped towards the flower to take a closer look, but almost immediately stopped in his tracks.

The flower started speaking.

“Howdy! I’m Flowey. Flowey the Flower!”

Riku simply continued to stare in shock. A talking flower? Was he dreaming? There was absolutely no way that this could be real. He shook his head, blinking a couple of times. Even pinched himself to make sure he wasn’t asleep. Nope, he was definitely awake.

The flower continued to talk. “Hmmm… You’re new to the underground, aren’tcha?”

Not sure of what else to do, the center nodded in response to the question of this strange flower. What else was he supposed to do, run? Already stressed as he was, running would only increase his chances of an attack. Besides, he didn’t know where to go. Riku wasn’t at all familiar with where he was right now.

“Golly, you must be so confused. Someone ought to teach you how things work around here! I guess little old me will have to do.” The flower winked, sticking out its tongue. If the situation weren’t so bizarre, Riku might’ve thought it was cute. “Ready? Here we go!”

All of a sudden, the scenery changed. Everything was shrouded in black, almost looking like an infinite void of darkness. A glowing red heart appeared in front of Riku’s chest. The boy attempted to touch it out of curiosity, but his hand simply phased through. Glancing around, he noticed that he was surrounded by white lines, shaped like a box around him. Heading over to one of the white lines, he attempted to step out, but a white wall immediately sprouted from the line, blocking his path. Looked like he wouldn’t be able to leave. Before Riku could question things any further, Flowey began to talk again.

“See that heart? That is your soul, the very culmination of your being!” Ah, so that’s what the heart was. “Your soul starts off weak, but can grow strong if you gain a lot of LV.”

Riku cocked his head to the side, confused. LV? Normally, he would’ve assumed it meant level, but this wasn’t a video game. Although, if you did try and explain this entire situation word for word to him a month ago, he would’ve told you that it was a fight scene from a game.

The flower seemed to read his mind, and continued. “What’s LV stand for? Why, love of course!” Okay, definitely not what Riku had expected. “You want some love, don’t you? Don’t worry, I’ll share some with you!”

That lightened the situation a little bit. Even if it were some weird sentient flower, love is something anyone would want to receive, right? Riku smiled slightly.

At that moment, white pellets seemed to appear around the two. The flower continued to explain. “Down here, love is shared through little white ‘friendliness pellets!’ Go on, move around! Get as many as you can!”

The pellets flew towards Riku, and following the flower’s instructions, the redhead stayed in place, waiting for the pellets to make contact with him. When they did… 

Everything began to hurt. Riku fell to the floor, breathing hard. He could feel an attack on its way; the stress, the shock, the panic, and now the added pain through his entire body, easily worsened his condition. He reached for his backpack, attempting to grab his inhaler, but everything hurt so badly that he had to stop his movements.

The flower grinned creepily. “You idiot,” it cackled. “In this world, it’s kill or be killed. Why would anyone pass up an opportunity like this?” A circle of pellets surrounded Riku, Flowey still smiling. There were no gaps that Riku could see, and even if there were, it wasn’t like he could get up and run between the pain and his attack.

Flowey’s laughter filled the room. “Die.” The bullets slowly closed around Riku, and now there was definitely no way of escape. That didn’t mean he was going to try though, as he attempted to get up and move.

To get up and just do something.

He struggled and struggled, trying to ignore his pain and his attack as the bullets moved closer and closer. Flowey’s laughter seemed even louder now.

Was this really how it was going to end?

Suddenly, the pellets disappeared, and Riku’s condition immediately improved. Both Flowey and Riku became silent and stilled their movements, confused. But before either of them could utter a word, what seemed to be a fireball flew in Flowey’s direction, and knocked the flower out of sight. Baffled, Riku looked around for the source. A soft voice reached his ears.

“What a terrible creature, torturing such a poor, innocent youth…”

**Notes for the Chapter:**

> Ooooo who is this???  
> I'm kidding, if you've ever played or seen Undertale then you know who it is.  
> Just thought I'd leave a cliffhanger owo  
> I hope you enjoyed this latest chapter ^^


End file.
